LONDON -- Guardian editor Alan Rusbridger on Tuesday vigorously defended his decision to publish a series of articles based on the secret files of former National Security Agency contractor Edward Snowden, telling a parliamentary committee hearing that the right to continue pursuing the story goes to the heart of press freedoms and democracy in Britain.

The hearing on the Guardian's handling of intelligence data leaked by Mr. Snowden, who is now living in self-imposed exile in Moscow, drew the attention of free-speech advocates on both sides of the Atlantic. Mr. Rusbridger faced more than an hour of questioning by Parliament's Home Affairs Select Committee on counterterrorism, testifying in what at times descended into a combative public grilling of both the Guardian and its editor.

Along with The Washington Post, the Guardian -- a London-based news outlet with a print circulation under 200,000 but online readers numbering in the many millions -- was the first to publish reports based on the Mr. Snowden leaks. In response, British authorities have acted far more aggressively than U.S. or other European officials, launching what Mr. Rusbridger and international free-speech advocates have decried as a campaign of "intimidation" against the paper. Actions taken so far include the coerced destruction of Snowden data being held at the Guardian's London headquarters and public denunciations by Prime Minister David Cameron, as well as the decision to summon Mr. Rusbridger for questioning by lawmakers on Tuesday.

During the hearing, a number of left-leaning politicians appeared to cheer the editor on for shedding light on the extreme lengths U.S. and British intelligence agencies have gone to in their global information-gathering efforts. But others, particularly Conservative lawmakers, challenged the decision to publish and pressed Mr. Rusbridger on whether he had personally violated British law.

Mark Reckless, a Conservative, questioned Mr. Rusbridger repeatedly about the Guardian's decision to share the trove of 58,000 Snowden files it had received -- including documents containing the names of British intelligence operatives -- with the New York Times. Names in the documents, Mr. Rusbridger said, were not redacted before being handed over because of the vast resources that would have required.

Mr. Reckless said the decision appeared to violate British counterterrorism laws.

The Guardian's right to publish the leaked Snowden files has been defended by leading free-speech advocates, with the hearing on Tuesday prompting several protest letters, including one in which U.S. journalist Carl Bernstein described Mr. Rusbridger's forced appearance Tuesday "dangerously pernicious." After the hearing, Padraig Reidy, spokesman for Index on Censorship, a London-based free-speech organization, called Mr. Rusbridger's grilling a worrying sign.

"The government has been reassuring us for the last few years that politicians will never interfere with the press," he said. Tuesday's interrogation showed that "when a story comes out they don't like, they start making threatening noises," he added.